Communication apparatus, communication method, and program for communicating with directional beams

ABSTRACT

A communication apparatus and corresponding method for performing wireless communication to include controlling deliver of content for plural programs using a directional beam, and notifying a terminal apparatus of first information regarding a timing of transmitting the directional beam in each of a plurality of directions in association with second information notified commonly to one or more of the terminal apparatuses within a communication range.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/770,075, filed Jun. 5, 2020, which is based on PCT filingPCT/JP2018/038009, filed Oct. 11, 2018, which claims priority to JP2017-239547, filed Dec. 14, 2017, the entire contents of each areincorporated herein by reference.

FIELD

The present disclosure relates to a communication apparatus, acommunication method, and a program.

BACKGROUND

Wireless access schemes and wireless networks of cellular mobilecommunication (hereinafter also referred to as “Long Term Evolution(LTE)”, “LTE-Advanced (LTE-A)”, “LTE-Advanced Pro (LTE-A Pro)”, “NewRadio (NR)”, “New Radio Access Technology (NRAT)”, “Evolved UniversalTerrestrial Radio Access (EUTRA)”, or “Further EUTRA (FEUTRA)”) areunder review in 3rd Generation Partnership Project (3GPP). Further, inthe following description, LTE includes LTE-A, LTE-A Pro, and EUTRA, andNR includes NRAT and FEUTRA. In LTE and NR, a base station device (basestation) is also referred to as an evolved Node B (eNodeB), a terminalapparatus (a mobile station, a mobile station device, or a terminal) isalso referred to as a user equipment (UE). LTE and NR are cellularcommunication systems in which a plurality of areas covered by a basestation device is arranged in a cell form. A single base station devicemay manage a plurality of cells.

In a fifth-generation (5G) mobile communication system followingLTE/LTE-A, technology using a directional beam for communication betweena base station and a terminal apparatus is being studied. The use ofsuch technology allows communication between a base station and aterminal apparatus to achieve spatial multiplexing in addition to timeand frequency multiplexing. In one example, Patent Document 1 disclosesan example of a technique using a directional beam for communicationbetween a base station and a terminal apparatus.

Further, as the technology for delivering content such as text, music,still images, and moving images to each terminal apparatus using theabove-described wireless network, a technology called multimediabroadcast and multicast service (MBMS) is studied. The use of the MBMStechnology makes it possible to efficiently deliver the above-mentionedvarious types of content that are broadcast as a program to a pluralityof terminal apparatuses via the wireless network.

Further background may be discerned from the following document:

-   Patent Literature 1: JP 2017-157908 A.

SUMMARY Technical Problem

On the other hand, in the fifth-generation (5G) mobile communicationsystem, data is transmitted to each terminal apparatus while a beamhaving directivity (also referred to hereinafter as a “directionalbeam”) is swept, and so the technique of delivering content to eachterminal apparatus within the communication range is different from thecommunication using a non-directional beam. Thus, even in a situationwhere a directional beam is used for communication, the technology suchas MBMS capable of efficiently delivering content provided as aso-called program (broadcasting program) to each terminal apparatus isdesirable to be applicable more suitably.

Thus, the present disclosure provides technology enabling the deliveryof content to a terminal apparatus using a directional beam to beachieved more suitably.

Solution to Problem

According to the disclosure, a communication apparatus is provided thatincludes: a communication unit configured to perform wirelesscommunication; a control unit configured to control delivery of contentfor each program using a directional beam; and a notification unitconfigured to notify a terminal apparatus of first information regardinga timing of transmitting the directional beam in each of a plurality ofdirections in association with second information notified commonly toone or more of the terminal apparatuses within a communication range.

Moreover, according to the disclosure, a communication apparatus isprovided that includes: a communication unit configured to performwireless communication; an acquisition unit configured to acquire, froma base station, second information associated with first informationregarding a timing of transmitting a directional beam used fordelivering content for each program in each of a plurality ofdirections, the second information being notified commonly to one ormore terminal apparatuses within a communication range of the basestation; and a control unit configured to controls in such a way as toreceive the content for each program on a basis of the acquired firstinformation.

Moreover, according to the disclosure, a communication method executedby a computer, the method is provided that includes: performing wirelesscommunication; controlling delivery of content for each program using adirectional beam; and notifying a terminal apparatus of firstinformation regarding a timing of transmitting the directional beam ineach of a plurality of directions in association with second informationnotified commonly to one or more of the terminal apparatuses within acommunication range.

Moreover, according to the disclosure, a communication method executedby a computer, the method is provided that includes: performing wirelesscommunication; acquiring, from a base station, second informationassociated with first information regarding a timing of transmitting adirectional beam used for delivering content for each program in each ofa plurality of directions, the second information being notifiedcommonly to one or more terminal apparatuses within a communicationrange of the base station; and controlling in such a way as to receivethe content for each program on a basis of the acquired firstinformation.

Moreover, according to the disclosure, a program is provided that causesa computer to execute: performing wireless communication; controllingdelivery of content for each program using a directional beam; andnotifying a terminal apparatus of first information regarding a timingof transmitting the directional beam in each of a plurality ofdirections in association with second information notified commonly toone or more of the terminal apparatuses within a communication range.

A program is provided that causes a computer to execute: performingwireless communication; acquiring, from a base station, secondinformation associated with first information regarding a timing oftransmitting a directional beam used for delivering content for eachprogram in each of a plurality of directions, the second informationbeing notified commonly to one or more terminal apparatuses within acommunication range of the base station; and controlling in such a wayas to receive the content for each program on a basis of the acquiredfirst information.

Advantageous Effects of Invention

According to the present disclosure as described above, the technologyis provided that enables the delivery of content to the terminalapparatus using the directional beam to be achieved more suitably.

Note that the effects described above are not necessarily limitative.With or in the place of the above effects, there may be achieved any oneof the effects described in this specification or other effects that maybe grasped from this specification.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an explanatory diagram illustrating an example of a schematicconfiguration of a system according to an embodiment of the presentdisclosure.

FIG. 2 is a block diagram illustrating an example of a configuration ofa base station according to the present embodiment.

FIG. 3 is a block diagram illustrating an example of a configuration ofa terminal apparatus according to the present embodiment.

FIG. 4 is an explanatory diagram illustrating an overview of MBMSnetwork architecture.

FIG. 5 is an explanatory diagram illustrating an example of a procedurefor performing “counting”.

FIG. 6 is a diagram illustrating an example of a protocol stack of an M1interface between an MBMS gateway and a base station.

FIG. 7 is a sequence diagram illustrating an example of an MBMS sessionstart procedure in LTE.

FIG. 8 shows an example of a frame structure upon using MBMS.

FIG. 9 is an explanatory diagram illustrating an overview of informationassociated with an MBMS session.

FIG. 10 is an explanatory diagram illustrating an overview ofinformation associated with an MBMS session.

FIG. 11 is an explanatory diagram illustrating an overview of a beamsweeping configuration.

FIG. 12 is an explanatory diagram illustrating an overview of the beamsweeping configuration.

FIG. 13 is an explanatory diagram illustrating an overview of beamsweeping configuration for each MBMS session.

FIG. 14 is a schematic sequence diagram illustrating an example of aprocedure for providing a program to each terminal apparatus using adirectional beam.

FIG. 15 is an explanatory diagram illustrating an example of a procedurefor providing a program to each terminal apparatus using a directionalbeam.

FIG. 16 is an explanatory diagram illustrating the relationship betweenthe beam reference sweeping and the beam sweeping for MBMS session.

FIG. 17 is a schematic sequence diagram illustrating an example of aprocedure between a base station and a terminal apparatus for providinga program to each terminal apparatus using a directional beam in acommunication system according to a first modification.

FIG. 18 is a schematic sequence diagram illustrating an example of aprocedure between a base station and a terminal apparatus for providinga program to each terminal apparatus using a directional beam in acommunication system according to a second modification.

FIG. 19 is an explanatory diagram illustrating an overview of acommunication system according to a third modification.

FIG. 20 is an explanatory diagram illustrating an overview of acommunication system according to a fourth modification.

FIG. 21 is a block diagram illustrating a first example of a schematicconfiguration of an eNB.

FIG. 22 is a block diagram illustrating a second example of theschematic configuration of the eNB.

FIG. 23 is a block diagram illustrating an example of a schematicconfiguration of a smartphone.

FIG. 24 is a block diagram illustrating an example of a schematicconfiguration of a car navigation apparatus.

DESCRIPTION OF EMBODIMENTS

Hereinafter, a preferred embodiment of the present disclosure will bedescribed in detail with reference to the appended drawings. Note that,in this specification and the appended drawings, structural elementsthat have substantially the same function and structure are denoted withthe same reference numerals, and repeated explanation of thesestructural elements is omitted.

Note that description will be provided in the following order.

1. Configuration Example

1.1. Configuration Example of System

1.2. Configuration Example of Base Station

1.3. Configuration example of terminal apparatus

2. MBMS

3. Technical features

4. Application examples

4.1. Application examples for base station

4.2. Application examples for terminal apparatus

5. Concluding remarks

1. Configuration Example

<1.1. Configuration Example of System>

An example of a schematic configuration of a system 1 according to anembodiment of the present disclosure is now described with reference toFIG. 1 . FIG. 1 is an explanatory diagram illustrating an example of aschematic configuration of the system 1 according to an embodiment ofthe present disclosure. As illustrated in FIG. 1 , the system 1 includesa wireless communication apparatus 100, a terminal apparatus 200, and anMEC server 300. The terminal apparatus 200 herein is also called a user.The user can also be called a UE. In other words, the above-described UE200 can correspond to the terminal apparatus 200 illustrated in FIG. 1 .The wireless communication apparatus 100C is also called UE-relay. TheUE herein can be a UE defined in LTE or LTE-A, and the UE-relay can bethe Prose-UE-to-Network relay, which is under development in 3GPP andcan refer to more typically communication equipment.

(1) Wireless Communication Apparatus 100

The wireless communication apparatus 100 is an apparatus that provides asubordinate device with a wireless communication service. In oneexample, the wireless communication apparatus 100A is a base station ofa cellular system (or a mobile communication system). The base station100A establishes wireless communication with a device located within acell 10A (e.g., the terminal apparatus 200A) of the base station 100A.In one example, the base station 100A transmits a downlink signal to theterminal apparatus 200A and receives an uplink signal from the terminalapparatus 200A.

The base station 100A establishes a logical connection with other basestations over, in one example, the X2 interface, and is capable oftransmitting and receiving control information or the like. In addition,the base station 100A establishes a logical connection with a corenetwork 40 over, in one example, the S1 interface, and is capable oftransmitting and receiving control information or the like. Moreover,communication between these apparatuses can be relayed through variousdevices physically.

In this description, the wireless communication apparatus 100Aillustrated in FIG. 1 is a macrocell base station, and the cell 10 is amacrocell. On the other hand, the wireless communication apparatuses100B and 100C are master devices that operate the small cells 10B and10C, respectively. As an example, the master device 100B is a fixedlyinstalled small cell base station. The small cell base station 100Bestablishes a wireless backhaul link with the macrocell base station100A and establishes an access link with one or more terminalapparatuses (e.g., the terminal apparatus 200B) within the small cell10B. Moreover, the wireless communication apparatus 100B can be a relaynode defined by 3GPP. The master device 100C is a dynamic access point(AP). The dynamic AP 100C is a mobile device that dynamically operatesthe small cell 10C. The dynamic AP 100C establishes a wireless backhaullink with the macrocell base station 100A and establishes an access linkwith one or more terminal apparatuses (e.g., the terminal apparatus200C) within the small cell 10C. The dynamic AP 100C can be, in oneexample, a terminal apparatus equipped with hardware or softwareoperable as a base station or a wireless access point. In this case, thesmall cell 10C is a dynamically configured localized network (virtualcell).

The cell 10 can be operated, in one example, in accordance with anywireless communication scheme such as LTE, LTE-Advanced (LTE-A), GSM(registered trademark), UMTS, W-CDMA, CDMA200, WiMAX, WiMAX2,IEEE802.16, and the like.

Moreover, the small cell is a concept that can include various types ofcells (e.g., such as femtocells, nanocells, picocells, and microcells)that are smaller than the macrocell and are arranged to overlap or notto overlap with the macrocell. In one example, a small cell is operatedby a dedicated base station. In another example, a small cell isoperated by a terminal acting as a master device that temporarilyoperates as a small cell base station. It is also possible for aso-called relay node to be considered as a form of small cell basestation. A wireless communication apparatus functioning as a masterstation of a relay node is also called a donor base station. The donorbase station can mean a DeNB in LTE, and can more generally refer to amaster station of a relay node.

(2) Terminal Apparatus 200

The terminal apparatus 200 is capable of performing communication in acellular system (or a mobile communication system). The terminalapparatus 200 performs wireless communication with a wirelesscommunication apparatus of the cellular system (e.g., the base station100A and the master device 100B or 100C). In one example, the terminalapparatus 200A receives a downlink signal from the base station 100A andtransmits an uplink signal to the base station 100A.

(3) Application Server 60

An application server 60 is a device that provides a user with aservice. The application server 60 is connected to a packet data network(PDN) 50. On the other hand, the base station 100 is connected to thecore network 40. The core network 40 is connected to the PDN 50 via agateway device (P-GW in FIG. 8 ). Thus, the wireless communicationapparatus 100 provides the MEC server 300 and the user with the serviceprovided by the application server 60, via the packet data network 50,the core network 40, and the wireless communication channel.

(4) MEC Server 300

The MEC server 300 is a service-providing device that provides a userwith a service (such as application and content). The MEC server 300 canbe provided in the wireless communication apparatus 100. In this case,the wireless communication apparatus 100 provides the user with theservice provided by the MEC server 300 via the wireless communicationchannel. The MEC server 300 can be implemented as a logical functionalentity or can be configured integrally with the wireless communicationapparatus 100 or the like as illustrated in FIG. 1 .

In one example, the base station 100A provides the terminal apparatus200A connected to the macrocell 10 with the service provided by the MECserver 300A. In addition, the base station 100A provides the terminalapparatus 2008 connected to the small cell 10B, via the master device1008, with the service provided by the MEC server 300A.

Further, the master device 100B provides the terminal apparatus 200Bconnected to the small cell 10B with the service provided by the MECserver 300B. Similarly, the master device 100C provides the terminalapparatus 200C connected to the small cell 10C with the service providedby the MEC server 300C.

(5) Supplement

Although the schematic configuration of the system 1 is described above,the present technology is not limited to the example illustrated in FIG.1 . Examples of the configuration of the system 1 can employ aconfiguration with no master device, a configuration of a small cellenhancement (SCE), a configuration of a heterogeneous network (HetNet),a configuration of a machine-type communication (MTC) network, or thelike.

<1.2. Configuration Example of Base Station>

A configuration of the base station 100 according to an embodiment ofthe present disclosure is now described with reference to FIG. 2 . FIG.2 is a block diagram illustrating an example of a configuration of thebase station 100 according to an embodiment of the present disclosure.Referring to FIG. 2 , the base station 100 includes an antenna unit 110,a wireless communication unit 120, a network communication unit 130, astorage unit 140, and a processing unit 150.

(1) Antenna Unit 110

The antenna unit 110 radiates a signal output by the wirelesscommunication unit 120 into space as a radio wave. In addition, theantenna unit 110 converts a radio wave in space into a signal andoutputs the signal to the wireless communication unit 120.

(2) Wireless Communication Unit 120

The wireless communication unit 120 transmits and receives a signal. Inone example, the wireless communication unit 120 transmits a downlinksignal to a terminal apparatus and receives an uplink signal from aterminal apparatus.

(3) Network Communication Unit 130

The network communication unit 130 transmits and receives information.In one example, the network communication unit 130 transmits andreceives information to and from other nodes. In one example, theabove-mentioned other nodes include other base stations and core networknodes.

Moreover, as described above, in the system 1 according to the presentembodiment, the terminal apparatus operates as a relay terminal to relaycommunication between a remote terminal and a base station in somecases. In such a case, in one example, the wireless communicationapparatus 100C corresponding to the relay terminal is not necessarilyprovided with the network communication unit 130.

(4) Storage Unit 140

The storage unit 140 temporarily or permanently stores various data anda program necessary for operating the base station 100.

(5) Processing Unit 150

The processing unit 150 allows the base station 100 to perform variousfunctions. The processing unit 150 includes a communication control unit151, an information acquisition unit 153, and a notification unit 155.Moreover, the processing unit 150 can further include other componentsbesides these components. In other words, the processing unit 150 canperform other operations than the operations of these components.

The operations of the communication control unit 151, the informationacquisition unit 153, and the notification unit 155 will be describedlater in detail.

<1.3. Configuration Example of Terminal Apparatus>

An example of a configuration of the terminal apparatus 200 according toan embodiment of the present disclosure is now described with referenceto FIG. 3 . FIG. 3 is a block diagram illustrating an example of aconfiguration of the terminal apparatus 200 according to an embodimentof the present disclosure. As illustrated in FIG. 3 , the terminalapparatus 200 includes an antenna unit 210, a wireless communicationunit 220, a storage unit 230, and a processing unit 240.

(1) Antenna Unit 210

The antenna unit 210 radiates a signal output by the wirelesscommunication unit 220 into space as a radio wave. In addition, theantenna unit 210 converts a radio wave in space into a signal andoutputs the signal to the wireless communication unit 220.

(2) Wireless Communication Unit 220

The wireless communication unit 220 transmits and receives a signal. Inone example, the wireless communication unit 220 receives a downlinksignal from a base station and transmits an uplink signal to a basestation.

Further, as described above, in the system 1 according to the presentembodiment, the terminal apparatus can operate as a relay terminal torelay communication between a remote terminal and the base station insome cases. In such a case, in one example, the wireless communicationunit 220 in the terminal apparatus 200C operating as a remote terminalcan transmit and receive a side-link signal to and from the relayterminal.

(3) Storage Unit 230

The storage unit 230 temporarily or permanently stores various data anda program necessary for operating the terminal apparatus 200.

(4) Processing Unit 240

The processing unit 240 allows the terminal apparatus 200 to performvarious functions. For example, the processing unit 240 includes acommunication control unit 241, an information acquisition unit 243, ameasuring unit 245, and a notification unit 247. Moreover, theprocessing unit 240 can further include other components besides thesecomponents. In other words, the processing unit 240 can perform otheroperations than the operations of these components.

The operations of the communication control unit 241, the informationacquisition unit 243, the measuring unit 245, and the notification unit247 will be described later in detail.

2. MBMS

A description of MBMS is now given. The MBMS is a technique fordelivering content such as text, music, still images, and moving imagesto each terminal apparatus using a wireless network and is officiallyreferred to as “multimedia broadcast multicast services”. Moreover, adescription of an overview of broadcast and multicast is given below tomake the characteristics of the communication system according to anembodiment of the present disclosure easier to understand.

The broadcast is a unidirectional point-to-multipoint downlinktransmission. The broadcast is unnecessary to communicate with a networkin providing the service, even in a power-saving state not connected tothe network, such as a so-called “RRC idle” state, the terminalapparatus is capable of receiving the delivery of a broadcast service.In other words, the terminal apparatus is capable of, even in the RRCidle state, receiving content that is broadcast from the base stationand presenting the content to the user.

The multicast is similar to the broadcast in that it provides aplurality of terminal apparatuses with a service. However, the multicastdiffers from the broadcast in that the terminal apparatus, uponreceiving a service, is necessary to indicate to the network that theterminal apparatus intends to receive the service. In other words, inthe multicast, the terminal apparatus necessitates communication withthe network to receive a service.

Moreover, in 5G, a high frequency of 6 GHz or more is usable, but ahigh-frequency band has higher propagation loss. Thus, to compensate forpropagation loss, a higher antenna gain is obtained by givingdirectivity to radio waves (wireless signals) by beamforming. For thisreason, the directivity is directed to a particular terminal apparatusby beamforming, so it is desirable to indicate that the terminalapparatus intends to receive the service corresponding to MBMS. In otherwords, in applying MBMS to the 5G mobile communication system, it ismore important to implement the delivery of content by multicast.Moreover, in the following description, the service corresponding toMBMS is also referred to as “MBMS service”.

(MBMS Network Architecture)

An overview of the MBMS network architecture is now described withreference to FIG. 4 . FIG. 4 is an explanatory diagram illustrating anoverview of the MBMS network architecture.

As illustrated in FIG. 4 , the MBMS network architecture includes a corenetwork (CN) and a radio access network (RAN). In addition, the CNincludes various entities. Examples of the entities included in the CNinclude mobility management entity (MME), home subscriber server (HSS),serving gateway (S-GW), packet data network gateway (P-GW), MBMSgateway, broadcast multicast service center (BM-SC), content server, andthe like. In addition, in the MBMS network architecture, an example ofan entity on the side of the RAN includes multi-cell/multicastcoordination entity (MCE). Moreover, among these entities, MCE, MBMSgateway, BM-SC, and content server are entities specific to MBMS, andthe other entities are similar to the entities used for unicastcommunication in LTE. In addition, the content to be provided in theMBMS service can be provided from inside the operator's network or canbe provided from the Internet network.

An overview of each of the entities specific to the MBMS, that is, theMCE, the MBMS gateway, the BM-SC, and the content server is nowdescribed.

(MCE)

A description of MCE is first given. As illustrated in FIG. 4 , the MCEis classified as an entity on the side of the RAN. The MCE can belocated in each base station (eNodeB) or can be located outside the basestation. Examples of the role of the MCE include three functions of“allocation of time and frequency resources for MBMS”, “decision ofmodulation and coding scheme (MCS)”, and “counting function”. Moreover,the MCS corresponds to a modulation scheme or coding rate. In addition,the counting function corresponds to a function of collecting how muchthe user is interested in the service. The counting function makes itpossible, in one example, for the base station to allocate time andfrequency resources for MBMS or stop the allocation depending on thenumber of interested users (i.e., the number of terminal apparatusesdesiring to deliver content).

Moreover, in LTE, an omnidirectional beam is used, so it is difficult tocontrol the MCS individually for each terminal apparatus. On the otherhand, in 5G, it is possible to allocate a beam individually to eachterminal apparatus, so in one example, it is also possible to providecontent (e.g., content corresponding to MBMS) using different MCSs foreach terminal apparatus.

In other words, in 5G, in one example, a situation can be assumed inwhich an MBMS service is provided to each terminal apparatus using aUE-specific beam. Even in a case where the handling between the basestation and the terminal apparatus is used like unicast (strictlyspeaking, it is multicast because similar content is delivered to aplurality of terminal apparatuses), the content is delivered usingmulticast (multicast for the IP layer) between the content server andthe base station. Thus, a function called counting is important tospecify which base station to perform multicasting.

For reference, an example of the existing procedure for performing thecounting is now described with reference to FIG. 5 . FIG. 5 is anexplanatory diagram illustrating an example of a procedure forperforming counting.

As illustrated in FIG. 5 , at first, an MCE 400 transmits an MBMSservice counting request to the base station 100 (S101). The basestation 100 receives the MBMS service counting request from the MCE 400and replies an MBMS service counting response to the MCE 400 (S103).Then, the base station 100 transmits an MBMS service counting request tothe terminal apparatus 200 (S105). The terminal apparatus 200 receivesthe MEMS service counting request from the base station 100 and repliesan MBMS service counting response to the base station 100 (S107). Then,the base station 100, when receiving the MBMS service counting responsefrom the terminal apparatus 200, transmits an MBMS service resultsreport to the MCE 400 (S109). The procedure as described above makes itpossible for the MCE 400 to recognize the number of terminal apparatusesthat desire to provide the MBMS service, in one example, on the basis ofthe report (the MBMS service results report) transmitted from the basestation 100.

(MBMS Gateway)

Subsequently, a description of the MBMS gateway is given. As illustratedin FIG. 4 , the MBMS gateway is an entity located in the CN. The MBMSgateway has a function of sending a packet to a corresponding basestation (eNodeB) using Internet protocol (IP) multicast address as akey. In LTE, MBMS is assumed only to use broadcast and does not supportmulticast. This means that the service does not support multicast. Onthe other hand, multicast is used for the IP layer. Specifically, inorder for the service to be broadcast to a plurality of terminalapparatuses, the previous signaling between the plurality of basestations and the MBMS gateway allows at least some of the base stationsto be specified and to be transferred only to the specified basestation. Thus, a multicast address is used in the IP layer.

In one example, FIG. 6 is a diagram illustrating an example of aprotocol stack of the M1 interface between the MBMS gateway and the basestation. Among the protocols illustrated in FIG. 6 , the layers of DASH,HTTP, TPC/UDP, and IP located on the upper side are not explicitlydescribed in the standard, but it is presumed that the configurationillustrated in FIG. 6 will be obtained in a case similar to the ordinaryunicast. In addition, the layers of GTPv1-U, UDP, IP, L2, and L1 locatedon the lower side are similar to the S1 interface in the unicast.Moreover, the IP layer used to transfer a packet to a plurality of basestations on the basis of the multicast address is an IP layer located onthe lower side.

In LTE, as described above, a packet is multicast from the MBMS gatewayto a plurality of base stations, and the plurality of base stationstransmit packets received in synchronization with each other to aterminal apparatus through wireless communication. On the other hand, in5G, an MBMS service is provided to each terminal apparatus using aUE-specific beam. Thus, a cache function is provided for the basestation, and the terminal apparatus is capable of optionally selectingthe time for receiving the MBMS service within a certain fixed period.

In 5G MBMS, caching of the content corresponding to MBMS (hereinafteralso referred to as “MBMS content”) in a base station makes it possibleto provide a terminal apparatus with a service more flexibly, resultingin expecting an effect of further reducing the CN traffic. In addition,it is possible to reduce resource consumption by MBMS on the side ofRAN, by transmitting content for each terminal apparatus using theUE-specific beam instead of transmitting content by the existingbroadcast or multicast on the side of RAN.

(BM-SC)

Subsequently, a description of BM-SC is given. The BM-SC corresponds tothe entry point of MBMS content. The BM-SC has the functions asdescribed below. As the first function, the BM-SC performs MBMS sessionmanagement. Specifically, the BM-SC manages the start and end of theMBMS service. As the second function, the BM-SC allocates an ID called atemporary mobile group identity (TMGI) to each MBMS session. As thethird function, the BM-SC allocates QoS to an MBMS session. As thefourth function, the BM-SC provides the terminal apparatus withinformation regarding broadcasting such as a program guide at theapplication level (TS29.061).

In LTE, the MBMS traffic and the unicast traffic are separated intosubframes. Specifically, a radio frame having a length of 1 ms isdivided into ten subframes having a length of 0.1 ms, and an MBMSservice is provided in some of the subframes. Thus, MEMS and unicast areseparate networks, and even if the unicast traffic increases, thesituation where the MBMS traffic is affected is extremely limited, inone example, as in the case or the like where the subframes allocated toMBMS are semi-statically changed. In a case where the MBMS service isprovided by unicast using a UE-specific beam, it can be assumed thatthere is a possibility that at least one of the ordinary unicast or theunicast of the MEMS service affects the other.

(Content Server)

Subsequently, a description of the content server is given. The contentserver is a server that provides content. The content server can belocated both inside and outside the operator's network.

(Session Start Procedure)

Subsequently, an example of an MBMS session start procedure in LTE isdescribed for reference to make the characteristics of the communicationsystem according to the present embodiment more understandable. In oneexample, FIG. 7 is a sequence diagram illustrating an example of theMBMS session start procedure in LTE.

As illustrated in FIG. 7 , the MEMS session start procedure starts froman MB-SC. Specifically, at first, an MB-SC 460 transmits a request tostart (Start Request) an MBMS session to an MBMS gateway 440 (S121). Inthis case, in one example, information such as a service area, QoS, anda mobile group identity (MGI) is notified through the request. The MBMSgateway 440 replies a response to the request (Start Response) from theMB-SC 460 (S123).

Subsequently, the MBMS gateway 440 transmits a request to start (StartRequest) the MBMS session to the MME 420 (S125). The MME 420, whenreceiving the request from the MBMS gateway 440, transmits a request tostart (Start Request) an MBMS session to the MCE 400 (S127). The MCE400, when receiving the request from the MME 420, replies a response(Start Response) to the MME 420 (S129). The MME 420, when receiving theresponse from the MCE 400, replies, to the MBMS gateway 440, a response(Start Response) to the request from the MBMS gateway 440 (S131).

Subsequently, the MCE 400 transmits a request to start (Start Request)the MBMS session to the base station 100 that is the service area(S133). In addition, the MCE 400 notifies the base station 100 ofinformation regarding the schedule of the MBMS session (Scheduling Info)(S135). The base station 100 replies, to the MCE 400, a response (StartResponse) to the request from the MCE 400 (S137). In addition, the basestation 100, when receiving the notification of the informationregarding the schedule of the MBMS session from the MCE 400, replies aresponse (Scheduling Info Response) to the MCE 400 (S139).

Subsequently, the base station 100, on the basis of the informationnotified from the MCE 400, transmits an MCCH change notification to theterminal apparatus 200 within the communication range (S141) and thentransmits MCCH/MCH/PMCH to the terminal apparatus 200 (S143). Moreover,the details of MCCH, MCH, and PMCH will be separately described later.

Subsequently, the target MBMS content is transferred from the MB-SC 460to the MBMS gateway 440, and the MBMS content is IP multicast from theMBMS gateway 440 to the base station 100 (S145). The base station 100,when receiving the MBMS content from the MBMS gateway 440, transmitsMCCH/MCH/PMCH to the terminal apparatus 200. In other words, the basestation 100 broadcasts the received MBMS content (S147).

The example of the MBMS session start procedure in LTE is describedabove with reference to FIG. 7 . On the other hand, there is apossibility that, in 5G NR, a procedure for starting a session from theterminal apparatus is added to the existing session start procedure.This is because it is possible to change the content delivery time foreach terminal apparatus in the MBMS service provided using theUE-specific beam.

(Radio Access Network of MBMS) Subsequently, the characteristics of theMBMS in the RAN is now described.

(1) Logical Channel for MBMS

The multimedia broadcast multicast service (MBMS) is provided over twological channels of multicast transport channel (MTCH) and multicastcontrol channel (MCCH). These two channels are mapped to PMCH (PHYMulticast Channel) as physical channels. In the PMCH, both the MCCH andthe MTCH are sent, and scheduling information for mapping between theMEMS session and the PMCH generated as MAC signaling is also sent. ThisMac signaling is sent in the header of the PMCH.

(2) Physical Channel for MBMS

The PMCH uses a cyclic prefix having a relatively long CP length calledextend CP. This is to constitute a single-frequency network forcombining signals from a plurality of base stations. In LTE, one radioframe has 10 subframes of which subframes in which MBMS single-frequencynetwork (MBSFN) is usable are designated semi-statically to be used. Inone example, FIG. 8 illustrates an example of a frame structure in acase of using the MBMS. In FIG. 8 , the marked subframes schematicallyshow subframes in which the MBSFN is usable. In addition, the markedframes schematically show a frame including a subframe in which theMBSFN is usable.

Some of the subframes for MBSFN are used for PDCCH and PDSCH, but thePDCCH is used not for MBMS but for transmission of uplink schedulinginformation necessary for ordinary unicast traffic. Thus, the PDSCHportion in the subframes for MBSFN is used for MBMS, and the PMCH istransmitted by the PDSCH.

(3) MBMS Session

In the present disclosure, one program is also referred to as an MBMSsession. In this case, the MBMS session is mapped to the PMCH (PHYMulticast Channel) that is the physical channel. In addition, the PMCHis mapped to a subframe allocated for the MBMS.

(4) MEMS Service Area

The MBMS service area corresponds to an area where one MBMS service isprovided. In addition, the MBSFN area corresponds to an area thatconstitutes a single-frequency network (SFN). In the MBSFN area, it ispossible to set up to eight areas for one base station. In a case wherethe SFN is configured, a plurality of base stations cooperates andtransmits the same content.

Moreover, in 5G, it can be assumed that the MBMS session is provided toeach terminal apparatus using the UE-specific beam. In the existingMBMS, the SFN technology described later is used, so it is not necessaryto consider handover. On the other hand, in 5G, a mechanismcorresponding to the MBMS handover is necessary due to theabove-described characteristics. Thus, in one example, it can benecessary to notify the number of the MBMS session from the switchingsource base station to the switching destination base station. In thisdescription, in a case where a beam necessary for beam recovery isprovided from another base station (e.g., a base station in an adjacentcell), it is also possible to reduce the latency by including the MBMSsession in a beam recovery request.

(5) SFN

The single-frequency network (SFN) is the technology in which the samesignal is transmitted simultaneously at the same time and frequency froma plurality of base stations (eNodeBs) and the plurality of downlinksignals is regarded as a reflected wave within the range of the cyclicprefix (CP), combined, and received, resulting in improving the signalstrength. In the case of broadcasting, a wide reception range of theterminal apparatus is necessary, so the SFN can be used in some cases.

(6) MBMS Scheduling

In some cases, it is difficult for a terminal apparatus to receive aprogram without knowing where the base station (eNodeB) transmits theprogram. In such a case, the terminal apparatus is necessary to acquirescheduling information (i.e., information indicating where transmissionis being performed).

The scheduling is performed in accordance with the procedure describedbelow. The details of each procedure are described below with referenceto FIG. 9 . FIG. 9 is an explanatory diagram illustrating an overview ofinformation associated with an MBMS session.

-   -   Specifying radio frame and subframe    -   MBSFN area configuration    -   Specifying MBMS session

(Specifying Radio Frame and Subframe)

The location of the MCCH is specified in the SIB 13 of the systeminformation. Specifically, the location of a radio frame including theMCCH is specified by a period and an offset. Furthermore, it isspecified which subframe in each radio frame includes the MCCH. Thelocation of the MCCH is actually the PMCH, so the MCCH is transmitted inthe PDSCH portion of the MBSFN subframe.

(MBSFN Area Configuration)

The MCCH includes the MBSFN area configuration. The MBSFN areaconfiguration specifies which subframe where the MBSFN is performed. Thespecifying of the subframe is settable by a period and an offset of aradio frame. In this case, it is possible to set simultaneously eighttypes of different periods and offsets for the specifying of thesubframe. In addition, which subframe in the radio frame is used is alsoset. Such an operation allows a subframe usable for MBMS to bedetermined. In the subframes for MBMS determined as described above, howto allocate the PMCH is also specified. The PMCH can set up to 16channels.

(Specifying of MBMS Session)

It is possible to set up to 30 MBMS sessions (i.e., programs) for 16PMCHs determined as described above. As a specific example, MBMSsessions 0 and 1 can be set for PMCH0, and MBMS sessions 2, 3, 4, 5, and6 can be set for PMCH1.

How to map the MBMS session to the PMCH is specified using the Macsignaling sent by the PMCH. The Mac signaling is a kind of RRC signalingin the SIB 13, so it is said that the MBMS scheduling is performed by acombination of RRC signaling and Mac signaling.

In 5G, it is conceivable that the MBMS session can be provided to eachterminal using the UE-specific beam. In this case, the SFN is notnecessary to be used, and there is a possibility that the terminalapparatus is able to receive the delivery of television broadcast at thedesired time. The content that is broadcast in the MBMS session istransmitted from the BM-SC to each base station (eNodeB) via the MBMSgateway. This content can be provided as a broadcast to the terminalapparatus at a time desired by the terminal apparatus as long as thecontent is held as a cache in the base station. In a case where thecache capacity has a physical limit, the expiration date can be given tothe information of the MBMS session disclosed in the SIB. The locationwhere the existing MBMS session is provided is disclosed on the PMCHspecified by the information of the radio frame and subframe and thelocation of the PMCH in the subframe. On the other hand, in the casewhere the MBMS service is provided using the beam, it is also possibleto disclose the information of the MBMS session as follows.

-   -   Disclosure is performed as before by system information embedded        in performing beamforming during beam management. Moreover, beam        management is a procedure for identifying an appropriate beam        between a base station and a terminal apparatus.    -   In a procedure after determining an appropriate beam between a        base station and a terminal apparatus, the provision of MBMS        information is notified on the downlink control channel (DCI).

(7) Entity for Receiving MBMS

The above-mentioned MBMS service can be provided to both the terminalapparatus in the RRC idle mode and the terminal apparatus in the RRCconnected mode. Thus, it is also possible for a terminal in the RRC idlemode to receive the various information described above.

(8) MCS (modulation scheme) used in MBMS

As described above in connection with the network architecture, in theexisting MBMS in LTE, the MCS can be changed by the MCE, but it is thebroadcasting, so the frequency to be changed is small. Thus, in theexisting MBMS in LTE, in one example, a common MCS that is preset forall terminal apparatuses is used.

On the other hand, in 5G, it is conceivable that the MBMS session isprovided to each terminal apparatus using a UE-specific beam. In such acase, it is possible to provide the MBMS service by changing the MCSbetween the base station and the terminal apparatus. Furthermore, in acase where the beam is blocked by an obstacle such as a person or a carlocated between the base station and the terminal apparatus, it isnecessary, in some cases, to switch the beam used for communication intothat from another base station. In such a case, there is a possibilitythat an MCS different from the MCS used in the beam before the switchingis used for the beam after the switching, and it can be assumed that theMCS before and after the switching is discontinuous.

(9) Feedback Information from Terminal Apparatus

The feedback information from a terminal apparatus is not specified inthe MBMS in LTE at present. There is the mixed mode in which bothordinary LTE and MBMS are operated, but even in this case, feedbackregarding the MBMS is not specified as a standard.

3. Technical Features

Technical features of the communication system according to anembodiment of the present disclosure are now described. As describedabove, in 5G MBMS, an MBMS service is assumed to be provided for eachterminal apparatus. The present disclosure thus focuses on a techniquefor enabling an MBMS service to be provided to each terminal apparatususing a cell-specific beam. More specifically, there is provided atechnique capable of controlling the MBMS service provision in acell-specific manner by providing a cell-specific beam in considerationof the position of a terminal apparatus or the like.

(Basic Configuration)

A basic configuration of the communication system according to anembodiment of the present disclosure is first described. In a 5Gnetwork, it is possible to provide the service using a millimeterwaveband from 6 GHz to 100 GHz. The radio waves from 6 GHz to 100 GHzhave a larger propagation loss than radio waves in a frequency band usedin a network based on standards such as LTE, so it is difficult to makethe radio waves reach far. For this reason, the transmission loss iscompensated in some cases by using the beamforming technique having ahigh antenna gain so that the transmission energy is concentrated in aparticular direction. From such a background, in 5G, an approach totransmit a control signal and a data signal using a beam havingdirectivity by the beamforming is studied. Moreover, in the followingdescription, a beam having directivity by the beamforming is alsoreferred to as a “directional beam” or simply “beam”.

On the other hand, the MBMS corresponds to so-called broadcasting, andit is necessary to deliver data to be broadcasting (hereinafter, alsoreferred to as “broadcasting data”) to terminal apparatuses of anunspecified number of users. In the existing LTE, broadcasting data isprovided to each terminal apparatus using an omnidirectional antenna. In5G, broadcasting data is provided by the beamforming technique using adirectional antenna as described above. Here, under the situation wherebroadcasting data is provided using a UE-specific beam for each terminalapparatus, in a case where a very large number of terminal apparatusesexist within the communication range of the base station, it isnecessary to allocate a beam to each of the terminal apparatuses in somecases. In such a case, a situation where the frequency and timeresources of a network are consumed more can be assumed.

In view of the above situation, the present disclosure provides anexample of a technique for providing broadcasting data (i.e., MBMScontent) using a beam common to each base station, that is, acell-specific beam. Information regarding a program to be broadcast(e.g., information regarding a beam corresponding to particularbroadcasting) is provided in an area of system information included in abeam of beam sweeping for synchronization. More specifically, in oneexample, for each program (i.e., MBMS session), the provision ofinformation indicating which beam of which subframe is provided isperformed.

In the related art (e.g., LTE), as described with reference to FIG. 9 ,after providing information regarding a subframe or the like,information indicating which program is included in the subframe isprovided. On the other hand, in 5G, after providing the informationregarding the program, then it is desirable to be notified of what beamis used (i.e., what kind of beam sweeping is used) to provideinformation for each program. With such a configuration, in one example,even in a case where a terminal apparatus desiring the delivery differsfor each program, it is possible to optimize settings of beam sweeping(e.g., a period of beam sweeping, the number of beams provided by beamsweeping, and beam direction provided by beam sweeping) for eachprogram.

The implementation of the above-described operation is desirable, in oneexample, to associate a resource configuration of beam sweeping with anMBMS session. The MBMS session is associated with one or more beamsweeping configurations capable of delivering the MBMS session. In oneexample, FIG. 10 is an explanatory diagram illustrating an overview ofinformation associated with an MBMS session. As illustrated in FIG. 10 ,the information regarding an MBMS session is first provided to aterminal apparatus as system information included in a beam fortransmitting a synchronization signal or the like (i.e., a beamtransmitted in the beam sweeping for synchronization). In other words,the information regarding the MBMS session is provided in associationwith the system information. Examples of the information regarding theMBMS session include an MBMS session ID for identifying a correspondingprogram, the beam sweeping configuration, and the like, as illustratedin FIG. 10 . Moreover, the information regarding the MBMS sessioncorresponds to an example of “first information”. In addition,information (e.g., system information) provided commonly to a pluralityof terminal apparatuses and associated with the information to provideinformation regarding the MBMS session to the terminal apparatuscorresponds to an example of “second information”.

An overview of the beam sweeping configuration is now described withreference to FIGS. 11 and 12 . FIG. 11 and FIG. 12 are explanatorydiagrams illustrating the overview of the beam sweeping configuration.As illustrated in FIG. 11 , the base station performs beam sweepingusing a plurality of beams every predetermined period (e.g., 10 ms or 20ms) as if it were a lighthouse light. Each beam transmitted by the beamsweeping includes, in one example, synchronization signal that is asignal for synchronization, system information, and the like, asillustrated in FIG. 12 . Each of a plurality of beams transmitted fromone base station by one time of beam sweeping (i.e., a plurality ofbeams belonging to the beam sweeping) includes system informationindicating common contents. This is because it is not necessary tochange the contents of system information for each beam due to thecharacteristics of providing information to an unspecified number ofterminal apparatuses. Thus, information common to each beam is providedas information regarding the MBMS session provided in association withthe system information (MBMS session information). Moreover, althoughthe example in which a beam including synchronization information isused is given in the above description, as long as a beam is intended toprovide system information, the beam may necessarily not include asynchronization signal.

In the examples illustrated in FIGS. 11 and 12 , the informationregarding the beam sweeping configuration is provided for each MBMSsession. The beam sweeping for each program indicated by the informationis thus performed separately from the beam sweeping for providing theinformation. In one example, in the case of the examples illustrated inFIGS. 11 and 12 , the beam sweeping is performed for each program by thenumber of MBMS sessions.

An overview of the beam sweeping configuration for each MBMS session isnow described with reference to FIG. 13 . FIG. 13 is an explanatorydiagram illustrating an overview of the beam sweeping configuration foreach MBMS session. As illustrated in FIG. 13 , the beam sweepingconfiguration for each MBMS session includes, in one example, settingsindicating when and on what resources the beam sweeping is performed. Inother words, the beam sweeping configuration includes, in one example,information regarding a timing at which a beam is transmitted(irradiated) in each of a plurality of directions, information regardinga frequency band usable in communication using the beam, and the like.

The beam sweeping configuration for each MBMS session includes, asillustrated in FIG. 13 , the settings indicating when and on whatresource the beam sweeping is performed. The example illustrated in FIG.13 shows that L beams are transmitted in one time of beam sweeping.Moreover, the L beams indicate beams transmitted in directions differentfrom each other. The terminal apparatus is difficult to recognize whichof the L beams is the beam transmitted in its own direction, so theterminal apparatus first attempts to receive all of the L beams. Then,the terminal apparatus identifies a beam that has higher received powerand capable of receiving the MBMS session desired to be delivered. Then,the terminal apparatus can be necessary to receive the previouslyidentified beam in accordance with the beam sweeping periodcorresponding to the MBMS session. As illustrated in FIG. 13 , the beamsweeping configuration for recognizing the time and frequency locationwhere the beam sweeping is being performed is set for the number of MBMSsessions.

An example of a procedure for providing a program to each terminalapparatus using a directional beam is now described with reference toFIG. 14 , by particularly focusing on the beam sweeping described above.FIG. 14 is a schematic sequence diagram illustrating an example of aprocedure for providing a program to each terminal apparatus using adirectional beam.

As illustrated in FIG. 14 , the base station 100 (the communicationcontrol unit 151) first performs the beam sweeping to provide systeminformation. This causes the base station 100 (the notification unit155) to notify the terminal apparatus 200 of the system information.This enables the terminal apparatus 200 (the information acquisitionunit 243) to acquire information regarding the beam sweepingconfiguration for each MBMS session from the system information notifiedfrom the base station 100 (S201).

Then, the base station 100 (the communication control unit 151)sequentially executes beam sweeping corresponding to the program (i.e.,the beam sweeping corresponding to the MBMS session) for each program onthe basis of the beam sweeping configuration for each MBMS session (S203a and S203 b). In addition, the base station 100 can periodicallyexecute the beam sweeping for each program at a predetermined period(S205 a and S205 b).

The description of the procedure illustrated in FIG. 14 is now given inmore detail with reference to FIG. 15 . FIG. 15 is an explanatorydiagram illustrating an example of the procedure for providing a programto each terminal apparatus using a directional beam and is a sequencediagram illustrating in more detail the procedure shown in FIG. 14 ,including the procedure for MBMS. Moreover, in FIG. 15 , the stepsdenoted by reference numerals S251 to S269 are substantially similar tothe steps denoted by reference numerals S121 to S139 in FIG. 7 ,respectively, and so a detailed description thereof is omitted.

In a case where the MB-SC 460 transfers (IP multicasts) the target MBMScontent to the MBMS gateway 440 (S271), the MBMS content is IP multicastfrom the MBMS gateway 440 to the base station 100 (S271). The basestation 100, when receiving the MBMS content from the MBMS gateway 440,first performs the beam sweeping to provide system information (S275).Moreover, the step indicated by reference numeral S275 corresponds tothe step indicated by reference numeral S201 in FIG. 14 .

Next, the base station 100 sequentially executes beam sweepingcorresponding to the program (i.e., the beam sweeping corresponding tothe MBMS session) for each program on the basis of the beam sweepingconfiguration for each MBMS session (S277 a and S277 b). Moreover, thestep indicated by reference numerals S277 a and S277 b corresponds tothe step indicated by reference numerals S203 a and S203 b in FIG. 14 .

Subsequently, in a case where the MB-SC 460 transfers (IP multicast) theMBMS content again to the MBMS gateway 440 (S281), the MBMS content isIP multicast from the MBMS gateway 440 to the base station 100 in asimilar manner to that described above (S283). The base station 100,when receiving the MBMS content from the MBMS gateway 440, executes thebeam sweeping corresponding to the program again for each program on thebasis of the beam sweeping configuration for each MEMS session (S285 aand S285 b). Moreover, the step indicated by reference numerals S285 aand S285 b corresponds to the step indicated by reference numerals S205a and S205 b in FIG. 14 .

The basic configuration of the communication system according to anembodiment of the present disclosure is described above with referenceto FIGS. 9 to 15 .

(First Modification)

Subsequently, a modification of the communication system according to anembodiment of the present disclosure is described. Moreover, the presentmodification is also referred to as a “first modification”.

In a case where delivery to an unspecified number of terminalapparatuses is assumed, it is desirable for the beam sweeping performedto provide a program to a terminal apparatus (i.e., beam sweepingperformed to deliver an MBMS session to a terminal apparatus) to providethe beam in as many directions as possible using many beams. Suchcontrol however causes limited frequency and time resources for the MBMSservice to be wasted, resulting in, in some cases, limiting thecommunication capacity for normal unicast downlink. From such abackground, in 5G MBMS, it is important to configure the beam sweepingmore suitably depending on the tendency of the terminal apparatusdesiring delivery.

Moreover, the function of a terminal apparatus requesting for deliveringan MBMS session (i.e., a terminal apparatus in which a user isinterested in a program) giving a notification to a base station isimplemented by a function called counting in LTE. In the presentmodification, there is provided technology enabling the terminalapparatus receiving the MBMS session to notify the base station ofinformation indicating the direction in which the beam transmitted forthe reception is being used, so that an extra beam sweeping is furtherreduced.

A description of an overview of the difference between counting and beamidentification (i.e., information indicating which beam is used forreception) is now given. In the counting, the base station is notifiedof which program the terminal apparatus desires to deliver. In LTE, theMBMS session is delivered using an omnidirectional antenna (i.e.,broadcasting is performed), so there is unnecessary to notify the basestation of which beam the terminal apparatus desires to deliver theprogram with using the beam. In 5G, in addition to information notifiedfrom a terminal apparatus to a base station in the existing counting(e.g., counting in LTE), in one example, information indicating whichbeam the program is desired to receive is necessary.

In view of such a situation, in the communication system according tothe present modification, the terminal apparatus gives a reportregarding beam sweeping for MBMS (i.e., beam report) to the basestation.

Specifically, first, the base station performs the beam referencesweeping for MBMS to provide beams in as many directions as possible foreach MBMS session. Each beam transmitted in the beam reference sweepingincludes a reference signal (reference signal) for measuring thereceived power of the beam. For the reference signal, different settingscan be applied to each beam, or common settings can be applied to aplurality of beams.

The terminal apparatus receives the beam transmitted by the beamreference sweeping for MBMS and identifies the desired beam forreceiving the content of the program corresponding to the desired MBMSsession on the basis of, in one example, reference signal received power(RSRP). Then, the terminal apparatus reports the beam ID of theidentified beam to the base station (performs beam reporting). Moreover,the information notified from the terminal apparatus to the base stationby the report corresponds to an example of “third information”. Inaddition, in other words, the terminal apparatus reports, as beamreporting, the content corresponding to the program is desired to bedelivered using which beam. In other words, like the above-mentionedreport (beam reporting) from the terminal apparatus to the base station,it can be said that information notified from the terminal apparatus tothe base station in order for the base station to perform countingcorresponds to an example of a request for delivery of contentcorresponding to the program.

Moreover, the period of beam reference sweeping is desirably set to beequal to or longer than the period of beam sweeping (the beam sweepingfor MBMS session) for transmitting the content of the programcorresponding to the MBMS session.

Further, the terminal apparatus does not necessarily notify a beam ID asbeam reporting for beam reference sweeping. This is because, in oneexample, in a case where any of a plurality of terminal apparatusesreports a corresponding beam ID to the base station, the base station iscapable of recognizing the corresponding beam is being used even if notall of the plurality of terminal apparatuses reports. On the other hand,in a case where at least some of the beams are not reported as beamreporting that the beam is necessary from any of the terminalapparatuses, the base station can be unnecessary to provide the contentof the program corresponding to the MEMS session using the beam. Thedetermination can be appropriately set depending on the implementationof the base station.

A description of the relationship between the beam reference sweepingand the beam sweeping for MBMS session is now given with reference toFIG. 16 . FIG. 16 is an explanatory diagram illustrating therelationship between the beam reference sweeping and the beam sweepingfor MBMS session. In one example, the period of the beam referencesweeping is set to be every 1 sec, and the period of the beam sweepingfor MBMS session is set to be every 10 ms. The number Z of beamsprovided by the beam reference sweeping is set to be equal to or largerthan the number L of beams provided by the beam sweeping for MBMSsession (Z L). Moreover, the beam reference sweeping corresponds to anexample of “second sweeping”, and a beam provided by the beam referencesweeping corresponds to an example of a “second directional beam”. Onthe other hand, the beam sweeping for MBMS session corresponds to anexample of “first sweeping”, and a beam provided by the beam sweepingfor MBMS session corresponds to an example of a “first directionalbeam”.

An example of a procedure between a base station and a terminalapparatus for providing a program to each terminal apparatus using adirectional beam in the communication system according to the presentmodification is now described with reference to FIG. 17 . FIG. 17 is aschematic sequence diagram illustrating an example of a procedurebetween a base station and a terminal apparatus for providing a programto each terminal apparatus using a directional beam in the communicationsystem according to the present modification. Moreover, for convenienceof description, a series of procedures are now described focusing on acase where the base station 100 delivers the MBMS content of the programcorresponding to the MBMS session (1).

As illustrated in FIG. 17 , the base station 100 (the communicationcontrol unit 151) first performs the beam sweeping to provide the systeminformation (S301). Subsequently, the base station 100 (thecommunication control unit 151) performs the beam reference sweeping foreach program. In other words, in the example illustrated in FIG. 17 ,the base station 100 performs the beam reference sweeping on the programcorresponding to the MBMS session (1) (S303). The terminal apparatus 200(the measuring unit 245) measures the RSRP of each beam transmitted fromthe base station 100 by the beam reference sweeping and identifies adesired beam to receive the content of the program corresponding to theMBMS session (1) depending on a result of the measurement. The terminalapparatus 200 (the notification unit 247) reports a beam ID of theidentified beam to the base station 100 (S305). Then, base station 100(the communication control unit 151) executes the beam sweeping (i.e.,the beam sweeping for MBMS session) for delivering the content of theprogram corresponding to the MBMS session (1) at a predetermined period(e.g., 10 ms) in response to the report from terminal apparatus 200(S307 a to S307 d).

Further, the base station 100 (the communication control unit 151)performs the beam reference sweeping for each program at a predeterminedperiod (e.g., 1 sec) (S309). In this case, the terminal apparatus 200measures the RSRP of each beam transmitted from the base station 100again by the beam reference sweeping and reports the beam ID of thespecified beam depending on a result of the measurement to the basestation 100 (S311). In addition, the base station 100 (the communicationcontrol unit 151) executes the beam sweeping for MBMS session inresponse to the report from the terminal apparatus 200 (S313 a to S313d).

The control as described above makes it also possible for the basestation 100 to limit the beam sweeping (e.g., limit the direction inwhich beams are transmitted, the number of beams, etc.) for deliveringthe content of the program for each program (i.e., for each MBMSsession) depending on the distribution of the terminal apparatuses 200that desire to deliver the program. In other words, the communicationsystem according to the first modification makes it possible to reducethe frequency of the occurrence of the situation where extra beamsweeping is performed (e.g., a situation where a beam is transmitted ina direction where there is no terminal apparatus 200 that desiresdelivery). This enables the communication system according to thepresent modification to optimize the use of frequency and time resourcesin the entire system depending on the situation.

(Second Modification)

Subsequently, a modification of the communication system according toanother embodiment of the present disclosure is described. Moreover, thepresent modification is also referred to as a “second modification”.

In the first modification, the measurement result (e.g., the measurementresult of RSRP) using the reference signal included in the beamtransmitted in the beam reference sweeping is reported from the terminalapparatus to the base station as the beam reporting.

On the other hand, in a case where the terminal apparatus sends anotification such as the beam reporting to the base station, theterminal apparatus is necessary to be in a state called RRC connected,that is, in a state where the terminal apparatus and the base stationcan communicate. In other words, in a case where the terminal apparatusis in a state where UL communication between the terminal apparatus andthe base station, which is called RRC idle, is restricted, the terminalapparatus is necessary to make a transition from the RRC idle state tothe RRC connected state for the beam reporting.

On the other hand, to make a transition of the state from RRC idle toRRC connected, predetermined signaling between the terminal apparatusand the base station is necessary. Such a situation in which signalingoccurs due to the state transition can be a heavy burden on a terminalapparatus that uses only the DL while maintaining the RRC idle state anddesires to receive the provision of the MBMS service. In addition, in asituation where an unspecified number of terminal apparatuses receivesthe provision of the MBMS service (i.e., a situation where the deliveryof MBMS content is received), a case where UL throughput is reduced canbe assumed by allocating UL resources individually to a plurality of theterminal apparatuses for beam reporting.

In view of such a situation, in the communication system according tothe present modification, the terminal apparatus performs the beamreporting using the random access procedure. Specifically, in thecommunication system according to the present modification, the terminalapparatus receives a beam transmitted from the base station in the beamreference sweeping and is provided with an area (window) for performingthe beam reporting on the base station. Under such a configuration, theterminal apparatus transmits UL using different sequences for each beamID within the range of the window. Moreover, in such a configuration, ULtransmissions from a plurality of terminal apparatuses collide withinthe window in some cases. Even in such a case, it is possible toseparate those having different sequences. In addition, a case where aplurality of terminal apparatuses performs the beam reporting for thesame beam ID can be assumed. In such a case, the same sequence is usedfor the same beam ID, so a collision of UL transmission from each of theplurality of terminal apparatuses occurs in some cases. Even in such acase, the base station is capable of recognizing that at least oneterminal apparatus desires to provide the MBMS service using the beamindicated by the beam ID, which is not a problem for system operation.

A description of an example of a procedure between a base station and aterminal apparatus for providing a program to each terminal apparatususing a directional beam in the communication system according to thepresent modification is now given with reference to FIG. 18 . FIG. 18 isa schematic sequence diagram illustrating an example of a procedurebetween a base station and a terminal apparatus for providing a programto each terminal apparatus using a directional beam in the communicationsystem according to the present modification. Moreover, for convenienceof description, a series of procedures are now described focusing on acase where the base station 100 delivers the MBMS content of the programcorresponding to the MBMS session (1).

As illustrated in FIG. 18 , the base station 100 (the communicationcontrol unit 151) first performs the beam sweeping to provide the systeminformation (S351). Subsequently, the base station 100 (thecommunication control unit 151) performs the beam reference sweeping foreach program. In other words, in the example illustrated in FIG. 18 ,the base station 100 performs the beam reference sweeping on the programcorresponding to the MBMS session (1) (S353). The terminal apparatus 200(the measuring unit 245) measures the RSRP of each beam transmitted fromthe base station 100 by the beam reference sweeping and identifies adesired beam to receive the content of the program corresponding to theMEMS session (1) depending on a result of the measurement. The terminalapparatus 200 (the notification unit 247) performs the beam reportingusing a sequence corresponding to the beam ID of the identified beamwithin the window provided for performing the beam reporting (S355).This allows the beam ID to be reported from the terminal apparatus 200to the base station 100.

Moreover, the subsequent processing is similar to the example describedwith reference to FIG. 17 . In other words, the steps denoted byreference numerals S357 a to S357 d and S363 a to S363 d aresubstantially similar to those of reference numerals S307 a to 307 d andS313 a to S313 d in FIG. 17 . In addition, the base station 100 (thecommunication control unit 151) can perform the beam reference sweepingfor each program at a predetermined period (e.g., 1 sec) (S359), whichis similar to the example illustrated in FIG. 17 . In this case, in oneexample, in a case where the terminal apparatus 200 is in the RRCconnected state, the terminal apparatus 200 can be necessary to performthe beam reporting in a similar manner to the procedure indicated by thereference numeral S311 in FIG. 17 . In addition, in a case where theterminal apparatus 200 is in the RRC idle state, the terminal apparatus200 can be necessary to perform the beam reporting in a similar mannerto the procedure indicated by reference numeral S355.

The control as described above makes it possible for the terminalapparatus 200 to perform the beam reporting to the base station 100 inthe RRC idle state. For this reason, it is unnecessary for the terminalapparatus 200 to make a transition to the RRC connected state to performthe beam reporting, resulting in reducing the processing load of theterminal apparatus 200. In addition, it is unnecessary for the terminalapparatus 200 to make a transition to the RRC connected state to performthe beaming reporting, so the frequency of signaling for making atransition from the RRC idle state to the RRC connected state isreduced, resulting in reducing the decrease in UL throughput due to thesignaling.

(Third Modification)

Subsequently, a modification of the communication system according toanother embodiment of the present disclosure is described. Moreover, thepresent modification is also referred to as a “third modification”.

The example in which the beam reference sweeping is performed for eachMBMS session (i.e., for each program) is described in the first andsecond modifications. On the other hand, in the present modification, anexample of a technique for further reducing the number of beams used forthe beam reference sweeping by sharing the beam reference sweepingbetween different MBMS sessions is described.

As described above, the terminal apparatus, when performing the beamreporting, notifies the base station of an MEMS session ID correspondingto the program desired to be delivered and a beam ID of the beam usedfor delivery of the content of the program. The terminal apparatus inthe RRC connected state can easily include the MBMS session ID and thebeam ID described above in the beam report.

On the other hand, as described in the second modification, in the casewhere the technique of transmitting a sequence in the random accessprocedure is applied, a window for transmitting the sequence can bedivided into a plurality of areas for each of the MBMS session ID andbeam ID described above. This makes it possible to transmit individuallya sequence for each MBMS session ID and beam ID.

In one example, FIG. 19 is an explanatory diagram illustrating anoverview of the communication system according to the presentmodification and illustrates an example of a method of dividing a windowfor transmitting a sequence in the random access procedure into areasfor each MBMS session ID and beam ID. In one example, in the exampleillustrated in FIG. 19 , the window is divided into a plurality of areasin the frequency direction and the time direction by TDM and FDM, and acombination of an MBMS session ID and a beam ID is associated with eachof the divided areas.

In other words, the terminal apparatus selects a resource correspondingto a beam used to deliver the content of the program from the resourcescorresponding to the program desired to be delivered (i.e., the MBMSsession ID) among the windows that are set as the resources forperforming the beam reporting. Then, the terminal apparatus performs ULtransmission using a predetermined sequence in the random accessprocedure using the selected resource. Moreover, in this case, allterminal apparatuses are capable of performing the reporting (i.e.,performing transmission of the sequence) using a common sequenceirrespective of the program desired to be delivered or the beam used fordelivering the content of the program.

The control as described above makes it possible for the communicationsystem according to the present modification to share the beam referencesweeping between different MBMS sessions, so the number of beams usedfor the beam reference sweeping can be further reduced. Thecommunication system according to the present modification thus makes italso possible to optimize resources used for communication in the entiresystem.

(Fourth Modification)

Subsequently, a modification of the communication system according toanother embodiment of the present disclosure is described. Moreover, thepresent modification is also referred to as a “fourth modification”.

In the first to third modifications, the examples are described in whichthe terminal apparatus performs the beam reporting every time the beamreference sweeping is performed. On the other hand, in the presentmodification, an example of a technique is described in which any one ofa plurality of terminal apparatuses performs the beam reporting asnecessary, thereby further reducing the load on the terminal apparatusassociated with the beam reporting.

Specifically, in a case where, for a certain session ID (a program), areport (i.e., beam reporting) of a beam ID (i.e., a beam used fordelivering the program) is made from any terminal apparatus to the basestation, the other terminal apparatuses do not necessarily make asimilar report (i.e., a request for delivering content using thecorresponding beam). This is because the base station is at leastcapable of recognizing that there is a terminal apparatus desiring todeliver the program corresponding to the session ID using the beamcorresponding to the beam ID by allowing at least some of the terminalapparatuses to report a beam ID for a certain session ID. On the otherhand, to implement the control as described above, the terminalapparatus is necessary to recognize whether the beam reporting is beingperformed (i.e., the use condition of the beam for each program) for acombination of a program to be delivered (i.e., a session ID) and a beamused for delivering the program (i.e., a beam ID).

In view of the above situation, in the communication system according tothe present modification, the base station provides the terminalapparatus with information indicating the use condition of the beam foreach program in association with information commonly notified to aplurality of terminal apparatuses such as system information.

In one example, FIG. 20 is an explanatory diagram illustrating anoverview of the communication system according to the presentmodification and schematically illustrates an example of the informationprovided from a base station to a terminal apparatus and indicating theuse condition of a beam for each program. Moreover, informationindicating the use condition of the beam for each program as illustratedin FIG. 20 corresponds to an example of “fourth information”.

The information denoted as “In use” in FIG. 20 indicates that thedelivery of the content by the beam associated with the information iscontinuing for the MBMS session associated with the information.

Further, the information denoted as “Beam reporting is required”indicates that the delivery of the content by the beam associated withthe information is continuing for the MEMS session associated with theinformation but indicates that the delivery may be stopped within agiven period of time. In other words, the delivery of the contentcorresponding to the MBMS session using the beam is stopped in the casewhere the beam reporting is not performed from any terminal apparatuswithin the period.

Further, another information except that described above (i.e.,information that is not hatched) indicates that the delivery of thecontent by the beam associated with the information is not performed forthe MBMS session associated with the information.

Under such a configuration, in a case where, in one example, theterminal apparatus does not desire to stop the delivery of the contentbased on the settings (i.e., the session ID and the beam ID) associatedwith the information indicated as “Beam reporting is required”, the beamreporting corresponding to the settings can be necessary to beperformed. Specifically, the terminal apparatus can measure thereference signal in the beam transmitted by the beam reference sweepingand can be necessary to perform the beam reporting depending on a resultof the measurement. In this case, the base station can modify theinformation corresponding to the session ID and the beam ID indicated bythe beam reporting transmitted from the terminal apparatus from “Beamreporting is required” to “In use”. Moreover, the beam transmitted bythe beam reference sweeping is capable of being received by any terminalapparatus within the communication range (cell), and so it correspondsto a cell-specific beam.

The control as described above enables the terminal apparatus torecognize, for the program desired to be delivered, the use condition ofthe beam for delivering the program to itself on the basis of theinformation provided from the base station. This allows the terminalapparatus to be necessary to perform the beam reporting to the basestation only in a case where, for example, delivery of the content ofthe program using the beam is stopped or can be probably stopped. Thismakes it possible to further reduce the load on the terminal apparatusby performing the beam reporting.

4. Application Examples

The technology according to the present disclosure can be applied tovarious products. For example, the base station 100 may be realized asany type of evolved Node B (eNB) such as a macro eNB or a small eNB. Thesmall eNB may be an eNB that covers a cell, such as a pico eNB, a microeNB, or a home (femto) eNB, smaller than a macrocell. Instead, the basestation 100 may be realized as another type of base station such as aNodeB or a base transceiver station (BTS). The base station 100 mayinclude a main entity (also referred to as a base station device) thatcontrols wireless communication and one or more remote radio heads(RRHs) disposed at different locations from the main entity. Further,various types of terminals to be described below may operate as the basestation 100 by performing a base station function temporarily orsemi-permanently. Further, at least one of constituent elements of thebase station 100 may be realized in the base station device or a modulefor the base station device.

Further, for example, the terminal apparatus 200 may be realized as amobile terminal such as a smartphone, a tablet personal computer (PC), anotebook PC, a portable game terminal, a portable/dongle mobile routeror a digital camera, or an in-vehicle terminal such as a car navigationapparatus. Further, the terminal apparatus 200 may be realized as aterminal that performs machine to machine (M2M) communication (alsoreferred to as a machine type communication (MTC) terminal). Further,the terminal apparatus 200 may be realized as a so-called “low costterminal”, such as an MTC terminal, an eMTC terminal, or an NB-IoTterminal. Moreover, at least a part of the constituent elements of theterminal apparatus 200 may be realized in a module mounted on theterminal (for example, an integrated circuit module configured on onedie).

<4.1. Application Examples for Base Station>

(First Application Example)

FIG. 21 is a block diagram illustrating a first example of a schematicconfiguration of an eNB to which the technology according to the presentdisclosure may be applied. An eNB 800 includes one or more antennas 810and a base station device 820. Each antenna 810 and the base stationdevice 820 may be connected to each other via an RF cable.

Each of the antennas 810 includes a single or a plurality of antennaelements (e.g., a plurality of antenna elements constituting a MIMOantenna) and is used for the base station device 820 to transmit andreceive a wireless signal. The eNB 800 may include the plurality of theantennas 810 as illustrated in FIG. 21 , and the plurality of antennas810 may, for example, correspond to a plurality of frequency bands usedby the eNB 800. It should be noted that while FIG. 21 illustrates anexample in which the eNB 800 includes the plurality of antennas 810, theeNB 800 may include the single antenna 810.

The base station device 820 includes a controller 821, a memory 822, anetwork interface 823, and a wireless communication interface 825.

The controller 821 may be, for example, a CPU or a DSP, and operatesvarious functions of an upper layer of the base station device 820. Forexample, the controller 821 generates a data packet from data in asignal processed by the wireless communication interface 825, andtransfers the generated packet via the network interface 823. Thecontroller 821 may generate a bundled packet by bundling data from aplurality of base band processors to transfer the generated bundledpacket. Further, the controller 821 may also have a logical function ofperforming control such as radio resource control, radio bearer control,mobility management, admission control, and scheduling. Further, thecontrol may be performed in cooperation with a surrounding eNB or a corenetwork node. The memory 822 includes a RAM and a ROM, and stores aprogram executed by the controller 821 and a variety of control data(such as, for example, terminal list, transmission power data, andscheduling data).

The network interface 823 is a communication interface for connectingthe base station device 820 to the core network 824. The controller 821may communicate with a core network node or another eNB via the networkinterface 823. In this case, the eNB 800 may be connected to a corenetwork node or another eNB through a logical interface (e.g., S1interface or X2 interface). The network interface 823 may be a wiredcommunication interface or a wireless communication interface forwireless backhaul. In the case where the network interface 823 is awireless communication interface, the network interface 823 may use ahigher frequency band for wireless communication than a frequency bandused by the wireless communication interface 825.

The wireless communication interface 825 supports a cellularcommunication system such as long term evolution (LTE) or LTE-Advanced,and provides wireless connection to a terminal located within the cellof the eNB 800 via the antenna 810. The wireless communication interface825 may typically include a base band (BB) processor 826, an RF circuit827, and the like. The BB processor 826 may, for example, performencoding/decoding, modulation/demodulation, multiplexing/demultiplexing,and the like, and performs a variety of signal processing on each layer(e.g., L1, medium access control (MAC), radio link control (RLC), andpacket data convergence protocol (PDCP)). The BB processor 826 may havepart or all of the logical functions as described above instead of thecontroller 821. The BB processor 826 may be a module including a memoryhaving a communication control program stored therein, a processor toexecute the program, and a related circuit, and the function of the BBprocessor 826 may be changeable by updating the program. Further, themodule may be a card or blade to be inserted into a slot of the basestation device 820, or a chip mounted on the card or the blade.Meanwhile, the RF circuit 827 may include a mixer, a filter, anamplifier, and the like, and transmits and receives a wireless signalvia the antenna 810.

The wireless communication interface 825 may include a plurality of theBB processors 826 as illustrated in FIG. 21 , and the plurality of BBprocessors 826 may, for example, correspond to a plurality of frequencybands used by the eNB 800. Further, the wireless communication interface825 may also include a plurality of the RF circuits 827, as illustratedin FIG. 21 , and the plurality of RF circuits 827 may, for example,correspond to a plurality of antenna elements. Note that FIG. 21illustrates an example in which the wireless communication interface 825includes the plurality of BB processors 826 and the plurality of RFcircuits 827, but the wireless communication interface 825 may includethe single BB processor 826 or the single RF circuit 827.

In the eNB 800 illustrated in FIG. 21 , one or more constituent elements(for example, at least one of the communication control unit 151, theinformation acquisition unit 153, or the notification unit 155) includedin the processing unit 150 described with reference to FIG. 2 may beimplemented in the wireless communication interface 825. Alternatively,at least some of the constituent elements may be implemented in thecontroller 821. As one example, a module including a part or the wholeof (for example, the BB processor 826) of the wireless communicationinterface 825 and/or the controller 821 may be implemented on the eNB800. The one or more constituent elements in the module may beimplemented in the module. In this case, the module may store a programcausing a processor to function as the one or more constituent elements(in other words, a program causing the processor to execute operationsof the one or more constituent elements) and execute the program. Asanother example, a program causing the processor to function as the oneor more constituent elements may be installed in the eNB 800, and thewireless communication interface 825 (for example, the BB processor 826)and/or the controller 821 may execute the program. In this way, the eNB800, the base station device 820, or the module may be provided as adevice including the one or more constituent elements and a programcausing the processor to function as the one or more constituentelements may be provided. In addition, a readable recording medium onwhich the program is recorded may be provided.

Further, in the eNB 800 illustrated in FIG. 21 , the wirelesscommunication unit 120 described with reference to FIG. 2 may beimplemented in the wireless communication interface 825 (for example,the RF circuit 827). Further, the antenna unit 110 may be implemented inthe antenna 810. In addition, the network communication unit 130 may beimplemented in the controller 821 and/or the network interface 823.Further, the storage unit 140 may be implemented in the memory 822.

(Second Application Example)

FIG. 22 is a block diagram illustrating a second example of a schematicconfiguration of an eNB to which the technology according to the presentdisclosure may be applied. An eNB 830 includes one or more antennas 840,a base station device 850, and an RRH 860. Each of the antennas 840 andthe RRH 860 may be connected to each other via an RF cable. Further, thebase station device 850 and the RRH 860 may be connected to each otherby a high speed line such as optical fiber cables.

Each of the antennas 840 includes a single or a plurality of antennaelements (e.g., a plurality of antenna elements constituting a MIMOantenna), and is used for the RRH 860 to transmit and receive a wirelesssignal. The eNB 830 may include a plurality of the antennas 840 asillustrated in FIG. 22 , and the plurality of antennas 840 may, forexample, correspond to a plurality of frequency bands used by the eNB830. Note that FIG. 22 illustrates an example in which the eNB 830includes the plurality of antennas 840, but the eNB 830 may include thesingle antenna 840.

The base station device 850 includes a controller 851, a memory 852, anetwork interface 853, a wireless communication interface 855, and aconnection interface 857. The controller 851, the memory 852, and thenetwork interface 853 are similar to the controller 821, the memory 822,and the network interface 823 described with reference to FIG. 21 .

The wireless communication interface 855 supports a cellularcommunication system such as LTE and LTE-Advanced, and provides wirelessconnection to a terminal located in a sector corresponding to the RRH860 via the RRH 860 and the antenna 840. The wireless communicationinterface 855 may typically include a BB processor 856 or the like. TheBB processor 856 is similar to the BB processor 826 described withreference to FIG. 21 except that the BB processor 856 is connected to anRF circuit 864 of the RRH 860 via the connection interface 857. Thewireless communication interface 855 may include a plurality of the BBprocessors 856, as illustrated in FIG. 21 , and the plurality of BBprocessors 856 may, for example, correspond to a plurality of frequencybands used by the eNB 830. Note that FIG. 22 illustrates an example inwhich the wireless communication interface 855 includes the plurality ofBB processors 856, but the wireless communication interface 855 mayinclude the single BB processor 856.

The connection interface 857 is an interface for connecting the basestation device 850 (wireless communication interface 855) to the RRH860. The connection interface 857 may be a communication module forcommunication on the high speed line which connects the base stationdevice 850 (wireless communication interface 855) to the RRH 860.

Further, the RRH 860 includes a connection interface 861 and a wirelesscommunication interface 863.

The connection interface 861 is an interface for connecting the RRH 860(wireless communication interface 863) to the base station device 850.The connection interface 861 may be a communication module forcommunication on the high speed line.

The wireless communication interface 863 transmits and receives awireless signal via the antenna 840. The wireless communicationinterface 863 may typically include the RF circuit 864 or the like. TheRF circuit 864 may include a mixer, a filter, an amplifier and the like,and transmits and receives a wireless signal via the antenna 840. Thewireless communication interface 863 may include a plurality of the RFcircuits 864 as illustrated in FIG. 22 , and the plurality of RFcircuits 864 may, for example, correspond to a plurality of antennaelements. Note that FIG. 22 illustrates an example in which the wirelesscommunication interface 863 includes the plurality of RF circuits 864,but the wireless communication interface 863 may include the single RFcircuit 864.

In the eNB 830 illustrated in FIG. 22 , one or more constituent elements(at least one of the communication control unit 151, the informationacquisition unit 153, or the notification unit 155) included in theprocessing unit 150 described with reference to FIG. 2 may beimplemented in the wireless communication interface 855 and/or thewireless communication interface 863. Alternatively, at least some ofthe constituent elements may be implemented in the controller 851. Asone example, a module including a part or the whole of (for example, theBB processor 856) of the wireless communication interface 855 and/or thecontroller 851 may be implemented on the eNB 830. The one or moreconstituent elements in the module may be implemented in the module. Inthis case, the module may store a program causing a processor tofunction as the one or more constituent elements (in other words, aprogram causing the processor to execute operations of the one or moreconstituent elements) and execute the program. As another example, aprogram causing the processor to function as the one or more constituentelements may be installed in the eNB 830, and the wireless communicationinterface 855 (for example, the BB processor 856) and/or the controller851 may execute the program. In this way, the eNB 830, the base stationdevice 850, or the module may be provided as a device including the oneor more constituent elements and a program causing the processor tofunction as the one or more constituent elements may be provided. Inaddition, a readable recording medium on which the program is recordedmay be provided.

Further, in the eNB 830 illustrated in FIG. 22 , for example, thewireless communication unit 120 described with reference to FIG. 2 maybe implemented in the wireless communication interface 863 (for example,the RF circuit 864). Further, the antenna unit 110 may be implemented inthe antenna 840. In addition, the network communication unit 130 may beimplemented in the controller 851 and/or the network interface 853.Further, the storage unit 140 may be implemented in the memory 852.

<4.2. Application Examples for Terminal Apparatus>

(First Application Example)

FIG. 23 is a block diagram illustrating an example of a schematicconfiguration of a smartphone 900 to which the technology according tothe present disclosure may be applied. The smartphone 900 includes aprocessor 901, a memory 902, a storage 903, an external connectioninterface 904, a camera 906, a sensor 907, a microphone 908, an inputdevice 909, a display device 910, a speaker 911, a wirelesscommunication interface 912, one or more antenna switches 915, one ormore antennas 916, a bus 917, a battery 918, and an auxiliary controller919.

The processor 901 may be, for example, a CPU or a system on chip (SoC),and controls the functions of an application layer and other layers ofthe smartphone 900. The memory 902 includes a RAM and a ROM, and storesa program executed by the processor 901 and data. The storage 903 mayinclude a storage medium such as semiconductor memories and hard disks.The external connection interface 904 is an interface for connecting thesmartphone 900 to an externally attached device such as memory cards anduniversal serial bus (USB) devices.

The camera 906 includes, for example, an image sensor such as chargecoupled devices (CCDs) and complementary metal oxide semiconductor(CMOS), and generates a captured image. The sensor 907 may include asensor group including, for example, a positioning sensor, a gyrosensor, a geomagnetic sensor, an acceleration sensor and the like. Themicrophone 908 converts a sound that is input into the smartphone 900 toan audio signal. The input device 909 includes, for example, a touchsensor which detects that a screen of the display device 910 is touched,a key pad, a keyboard, a button, a switch or the like, and accepts anoperation or an information input from a user. The display device 910includes a screen such as liquid crystal displays (LCDs) and organiclight emitting diode (OLED) displays, and displays an output image ofthe smartphone 900. The speaker 911 converts the audio signal that isoutput from the smartphone 900 to a sound.

The wireless communication interface 912 supports a cellularcommunication system such as LTE or LTE-Advanced, and performs wirelesscommunication. The wireless communication interface 912 may typicallyinclude the BB processor 913, the RF circuit 914, and the like. The BBprocessor 913 may, for example, perform encoding/decoding,modulation/demodulation, multiplexing/demultiplexing, and the like, andperforms a variety of types of signal processing for wirelesscommunication. On the other hand, the RF circuit 914 may include amixer, a filter, an amplifier, and the like, and transmits and receivesa wireless signal via the antenna 916. The wireless communicationinterface 912 may be a one-chip module in which the BB processor 913 andthe RF circuit 914 are integrated. The wireless communication interface912 may include a plurality of BB processors 913 and a plurality of RFcircuits 914 as illustrated in FIG. 23 . Note that FIG. 23 illustratesan example in which the wireless communication interface 912 includes aplurality of BB processors 913 and a plurality of RF circuits 914, butthe wireless communication interface 912 may include a single BBprocessor 913 or a single RF circuit 914.

Further, the wireless communication interface 912 may support othertypes of wireless communication system such as a short range wirelesscommunication system, a near field communication system, and a wirelesslocal area network (LAN) system in addition to the cellularcommunication system, and in this case, the wireless communicationinterface 912 may include the BB processor 913 and the RF circuit 914for each wireless communication system.

Each antenna switch 915 switches a connection destination of the antenna916 among a plurality of circuits (for example, circuits for differentwireless communication systems) included in the wireless communicationinterface 912.

Each of the antennas 916 includes one or more antenna elements (forexample, a plurality of antenna elements constituting a MIMO antenna)and is used for transmission and reception of the wireless signal by thewireless communication interface 912. The smartphone 900 may include aplurality of antennas 916 as illustrated in FIG. 23 . Note that FIG. 23illustrates an example in which the smartphone 900 includes a pluralityof antennas 916, but the smartphone 900 may include a single antenna916.

Further, the smartphone 900 may include the antenna 916 for eachwireless communication system. In this case, the antenna switch 915 maybe omitted from a configuration of the smartphone 900.

The bus 917 connects the processor 901, the memory 902, the storage 903,the external connection interface 904, the camera 906, the sensor 907,the microphone 908, the input device 909, the display device 910, thespeaker 911, the wireless communication interface 912, and the auxiliarycontroller 919 to each other. The battery 918 supplies electric power toeach block of the smartphone 900 illustrated in FIG. 23 via a feederline that is partially illustrated in the figure as a dashed line. Theauxiliary controller 919, for example, operates a minimally necessaryfunction of the smartphone 900 in a sleep mode.

In the smartphone 900 illustrated in FIG. 23 , one or more constituentelements included in the processing unit 240 (at least one of thecommunication control unit 241, the information acquisition unit 243,the measuring unit 245, or the notification unit 247) described withreference to FIG. 3 may be implemented in the wireless communicationinterface 912. Alternatively, at least some of the constituent elementsmay be implemented in the processor 901 or the auxiliary controller 919.As one example, a module including a part or the whole of (for example,the BB processor 913) of the wireless communication interface 912, theprocessor 901, and/or the auxiliary controller 919 may be implemented onthe smartphone 900. The one or more constituent elements in the modulemay be implemented in the module. In this case, the module may store aprogram causing a processor to function as the one or more constituentelements (in other words, a program causing the processor to executeoperations of the one or more constituent elements) and execute theprogram. As another example, a program causing the processor to functionas the one or more constituent elements may be installed in thesmartphone 900, and the wireless communication interface 912 (forexample, the BB processor 913), the processor 901, and/or the auxiliarycontroller 919 may execute the program. In this way, the smartphone 900or the module may be provided as a device including the one or moreconstituent elements and a program causing the processor to function asthe one or more constituent elements may be provided. In addition, areadable recording medium on which the program is recorded may beprovided.

Further, in the smartphone 900 illustrated in FIG. 23 , for example, thewireless communication unit 220 described with reference to FIG. 3 maybe implemented in the wireless communication interface 912 (for example,the RF circuit 914). Further, the antenna unit 210 may be implemented inthe antenna 916. Further, the storage unit 230 may be implemented in thememory 902.

(Second Application Example)

FIG. 24 is a block diagram illustrating an example of a schematicconfiguration of a car navigation apparatus 920 to which the technologyaccording to the present disclosure may be applied. The car navigationapparatus 920 includes a processor 921, a memory 922, a globalpositioning system (GPS) module 924, a sensor 925, a data interface 926,a content player 927, a storage medium interface 928, an input device929, a display device 930, a speaker 931, a wireless communicationinterface 933, one or more antenna switches 936, one or more antennas937, and a battery 938.

The processor 921 may be, for example, a CPU or an SoC, and controls thenavigation function and the other functions of the car navigationapparatus 920. The memory 922 includes a RAM and a ROM, and stores aprogram executed by the processor 921 and data.

The GPS module 924 uses a GPS signal received from a GPS satellite tomeasure the position (e.g., latitude, longitude, and altitude) of thecar navigation apparatus 920. The sensor 925 may include a sensor groupincluding, for example, a gyro sensor, a geomagnetic sensor, abarometric sensor and the like. The data interface 926 is, for example,connected to an in-vehicle network 941 via a terminal that is notillustrated, and acquires data such as vehicle speed data generated onthe vehicle side.

The content player 927 reproduces content stored in a storage medium(e.g., CD or DVD) inserted into the storage medium interface 928. Theinput device 929 includes, for example, a touch sensor which detectsthat a screen of the display device 930 is touched, a button, a switchor the like, and accepts operation or information input from a user. Thedisplay device 930 includes a screen such as LCDs and OLED displays, anddisplays an image of the navigation function or the reproduced content.The speaker 931 outputs a sound of the navigation function or thereproduced content.

The wireless communication interface 933 supports a cellularcommunication system such as LTE or LTE-Advanced, and performs wirelesscommunication. The wireless communication interface 933 may typicallyinclude the BB processor 934, the RF circuit 935, and the like. The BBprocessor 934 may, for example, perform encoding/decoding,modulation/demodulation, multiplexing/demultiplexing, and the like, andperforms a variety of types of signal processing for wirelesscommunication. On the other hand, the RF circuit 935 may include amixer, a filter, an amplifier, and the like, and transmits and receivesa wireless signal via the antenna 937. The wireless communicationinterface 933 may be a one-chip module in which the BB processor 934 andthe RF circuit 935 are integrated. The wireless communication interface933 may include a plurality of BB processors 934 and a plurality of RFcircuits 935 as illustrated in FIG. 24 . Note that FIG. 24 illustratesan example in which the wireless communication interface 933 includes aplurality of BB processors 934 and a plurality of RF circuits 935, butthe wireless communication interface 933 may include a single BBprocessor 934 or a single RF circuit 935.

Further, the wireless communication interface 933 may support othertypes of wireless communication system such as a short range wirelesscommunication system, a near field communication system, and a wirelessLAN system in addition to the cellular communication system, and in thiscase, the wireless communication interface 933 may include the BBprocessor 934 and the RF circuit 935 for each wireless communicationsystem.

Each antenna switch 936 switches a connection destination of the antenna937 among a plurality of circuits (for example, circuits for differentwireless communication systems) included in the wireless communicationinterface 933.

Each of the antennas 937 includes one or more antenna elements (forexample, a plurality of antenna elements constituting a MIMO antenna)and is used for transmission and reception of the wireless signal by thewireless communication interface 933. The car navigation apparatus 920may include a plurality of antennas 937 as illustrated in FIG. 24 . Notethat FIG. 24 illustrates an example in which the car navigationapparatus 920 includes a plurality of antennas 937, but the carnavigation apparatus 920 may include a single antenna 937.

Further, the car navigation apparatus 920 may include the antenna 937for each wireless communication system. In this case, the antenna switch936 may be omitted from a configuration of the car navigation apparatus920.

The battery 938 supplies electric power to each block of the carnavigation apparatus 920 illustrated in FIG. 24 via a feeder line thatis partially illustrated in the figure as a dashed line. Further, thebattery 938 accumulates the electric power supplied from the vehicle.

In the car navigation apparatus 920 illustrated in FIG. 24 , one or moreconstituent elements included in the processing unit 240 (at least oneof the communication control unit 241, the information acquisition unit243, the measuring unit 245, or the notification unit 247) describedwith reference to FIG. 3 may be implemented in the wirelesscommunication interface 933. Alternatively, at least some of theconstituent elements may be implemented in the processor 921. As oneexample, a module including a part or the whole of (for example, the BBprocessor 934) of the wireless communication interface 933 and/or theprocessor 921 may be implemented on the car navigation apparatus 920.The one or more constituent elements in the module may be implemented inthe module. In this case, the module may store a program causing aprocessor to function as the one or more constituent elements (in otherwords, a program causing the processor to execute operations of the oneor more constituent elements) and execute the program. As anotherexample, a program causing the processor to function as the one or moreconstituent elements may be installed in the car navigation apparatus920, and the wireless communication interface 933 (for example, the BBprocessor 934) and/or the processor 921 may execute the program. In thisway, the car navigation apparatus 920 or the module may be provided as adevice including the one or more constituent elements and a programcausing the processor to function as the one or more constituentelements may be provided. In addition, a readable recording medium onwhich the program is recorded may be provided.

Further, in the car navigation apparatus 920 illustrated in FIG. 24 ,for example, the wireless communication unit 220 described withreference to FIG. 3 may be implemented in the wireless communicationinterface 933 (for example, the RF circuit 935). Further, the antennaunit 210 may be implemented in the antenna 937. Further, the storageunit 230 may be implemented in the memory 922.

The technology of the present disclosure may also be realized as anin-vehicle system (or a vehicle) 940 including one or more blocks of thecar navigation apparatus 920, the in-vehicle network 941, and a vehiclemodule 942. In other words, the in-vehicle system (or the vehicle) 940may be provided as a device including at least one of the communicationcontrol unit 241, the information acquisition unit 243, the measuringunit 245, or the notification unit 247. The vehicle module 942 generatesvehicle data such as vehicle speed, engine speed, and troubleinformation, and outputs the generated data to the in-vehicle network941.

5. Concluding Remarks

As described above, in the communication system according to anembodiment of the present disclosure, the base station notifiesinformation regarding an MBMS session (e.g., information such as timingsat which beams are transmitted in each of a plurality of directions) tothe terminal apparatus. In this case, the information is associated withinformation (e.g., system information) notified commonly to one or moreterminal apparatuses within a communication range. The terminalapparatus controls in such a way that the content of the desired programis received on the basis of the information notified from the basestation. As a specific example, the terminal apparatus recognizes thetiming at which the beam for transmitting the content of the desiredprogram is transmitted toward itself and receives the content dependingon the timing on the basis of the information notified from the basestation.

The configuration as described above makes it possible for the basestation to deliver efficiently the content (the MBMS content) of theprogram desired to be delivered to each terminal apparatus within thecommunication range using a UE-specific beam. Such a configurationallows the communication system according to an embodiment of thepresent disclosure to improve the utilization efficiency of networkresources, that is, to accommodate efficiently a terminal apparatus thatdesires to deliver MBMS content. The communication system according toan embodiment of the present disclosure thus allows an effect of furtherimproving the throughput of the entire system to be expected.

The preferred embodiment of the present disclosure has been describedabove with reference to the accompanying drawings, whilst the technicalscope of the present disclosure is not limited to the above examples. Aperson skilled in the art may obviously find various alterations andmodifications within the scope of the technical idea described in theappended claims, and it should be understood that they will naturallycome under the technical scope of the present disclosure.

Further, the effects described in this specification are merelyillustrative or exemplified effects, and are not limitative. That is,with or in the place of the above effects, the technology according tothe present disclosure may achieve other effects that are clear to thoseskilled in the art from the description of this specification.

REFERENCE SIGNS LIST

-   1 System-   10 Cell-   40 Core network-   50 Packet data network-   60 Application server-   100 Base station-   110 Antenna unit-   120 Wireless communication unit-   130 Network communication unit-   140 Storage unit-   150 Processing unit-   151 Communication control unit-   153 Information acquisition unit-   155 Notification unit-   200 Terminal apparatus-   210 Antenna unit-   220 Wireless communication unit-   230 Storage unit-   240 Processing unit-   241 Communication control unit-   243 Information acquisition unit-   245 Measuring unit-   247 Notification unit-   300 MEC server

The invention claimed is:
 1. A communication apparatus configured as abase station and comprising: a transceiver configured to performwireless communication; control circuitry operatively connected to thetransceiver and configured to deliver content corresponding to one ormore programs using one of a plurality of directional beams, each ofplurality of directional beams allocated individually to the one or moreof the programs, wherein the control circuitry is configured to causethe base station to: notify a terminal apparatus of first informationidentifying a program of the one or more programs that is to bebroadcast in a directional beam of the plurality of directional beams ineach of a plurality of directions, the first information being notifiedto the terminal apparatus in association with second informationnotified commonly to one or more of terminal apparatuses within acommunication range, the one or more of terminal apparatuses includingthe terminal apparatus, notify the terminal apparatus of resourceinformation regarding a time and frequency resource of the directionalbeam, and after notifying the terminal apparatus of the resourceinformation, provide content corresponding to the program to theterminal apparatus via the directional beam in accordance with thenotified time and frequency resource.
 2. The communication apparatusaccording to claim 1, wherein the second information is systeminformation.
 3. The communication apparatus according to claim 1,wherein the control circuitry further causes the base station to sweepof the directional beam to deliver the content corresponding to theprogram using the directional beam.
 4. The communication apparatusaccording to claim 3, wherein the control circuitry further causes thebase station to sweep the directional beam individually for each of theone or more programs.
 5. The communication apparatus according to claim4, wherein at least any one of a period of the sweeping, a number of thedirectional beams transmitted in the sweeping, or a direction oftransmission of the directional beam in the sweeping is set for each ofthe one or more programs.
 6. A communication apparatus configured as aterminal apparatus and comprising: a transceiver configured to performwireless communication; control circuitry operatively connected to thetransceiver and configured to receive content corresponding to one ormore programs using one of a plurality of directional beams, each ofplurality of directional beams allocated individually to the one or moreof the programs, wherein the control circuitry further causes theterminal apparatus to: receive first information identifying a programof the one or more programs that is to be broadcast in a directionalbeam of the plurality of directional beams in each of a plurality ofdirections, the first information being received in association withsecond information notified commonly to one or more of terminalapparatuses within a communication range, the one or more of terminalapparatuses including the terminal apparatus, receive resourceinformation regarding a time and frequency resource of the directionalbeam, and after receiving the resource information, receive contentcorresponding to the program via the directional beam in accordance withthe notified time and frequency resource.
 7. The communication apparatusaccording to claim 1, wherein the second information is systeminformation.
 8. A method performed by a communication apparatusconfigured as a base station, the method comprising: performing wirelesscommunication; and performing a process for delivering contentcorresponding to one or more programs using one of a plurality ofdirectional beams, each of plurality of directional beams allocatedindividually to the one or more of the programs, wherein the processcomprises: notifying a terminal apparatus of first informationidentifying a program of the one or more programs that is to bebroadcast in a directional beam of the plurality of directional beams ineach of a plurality of directions, the first information being notifiedto the terminal apparatus in association with second informationnotified commonly to one or more of terminal apparatuses within acommunication range, the one or more of terminal apparatuses includingthe terminal apparatus; notifying the terminal apparatus of resourceinformation regarding a time and frequency resource of the directionalbeam; and after notifying the terminal apparatus of the resourceinformation, providing content corresponding to the program to theterminal apparatus via the directional beam in accordance with thenotified time and frequency resource.
 9. A method performed by acommunication apparatus configured as a terminal apparatus, the methodcomprising: performing wireless communication; and performing a processfor receiving content corresponding to one or more programs using one ofa plurality of directional beams, each of plurality of directional beamsallocated individually to the one or more of the programs, wherein theprocess comprises: receiving first information identifying a program ofthe one or more programs that is to be broadcast in a directional beamof the plurality of directional beams in each of a plurality ofdirections, the first information being received in association withsecond information notified commonly to one or more of terminalapparatuses within a communication range, the one or more of terminalapparatuses including the terminal apparatus; receiving resourceinformation regarding a time and frequency resource of the directionalbeam; and after receiving the resource information, receiving contentcorresponding to the program via the directional beam in accordance withthe notified time and frequency resource.